Maricopa County officials will subpoena records that Sheriff Joe Arpaio's office has refused to turn over to U.S. Department of Justice lawyers who are investigating the police agency over allegations of discrimination and unconstitutional searches.

A lawyer for an Arizona sheriff known for his efforts against illegal immigrants said Thursday that the U.S. Justice Department's threat to sue over records for its civil rights investigation is premature because his client is willing to cooperate with certain elements of the probe.